J-Virus
J-Syndrome is when a person in the group goes missing with a dumb excuse, comes back later, and still expects to be in on everything even though they left everyone hanging.
Dropped out of the group trip to 'find their keys' and came back to say they wanted to ride the roller coaster too.
Left the hangout to 'look for a lost pet' and showed up 3 hours later to complain about the snacks.
Exited the chat to 'do a quick errand' and came back to say they wanted to know all the inside jokes.